1. Field of the Invention
The present invention relates to corrugator belts, and more particularly to a corrugator belt structure incorporating a spiral coil carrier having either a fibrous batt secured thereto or having a foam coating thereon, for engagement with a surface of a corrugated sheet.
2. Description of the Prior Art
Corrugator belts are used in corrugating machines to feed sheet material through the machine, as well as to apply pressure to the sheet material to facilitate joining together of the several sheets of material forming a sheet of faced corrugated paperboard. Conventional corrugating machine belts are normally either a woven fabric or, alternatively, a woven fabric carrier that has a batt of fabric material needled thereto that is adapted to come into direct contact with and bear against a surface of the sheet material that passes through the corrugating machine. The conventional corrugator belts presently in use have a number of shortcomings. Included within those shortcomings is a tendency for the belts to wear at the outer edges thereof, when a narrow sheet of corrugated board is being formed, as a result of sagging of the belt edges and rubbing along the heater unit that is provided to dry the glue used to adhere the respective individual facing sheet or sheets that are combined to form a composite sheet of corrugated paperboard.
In addition to edge wear, the present corrugator belts also include heavy metal hooks that join together the ends of the belt to thereby form an endless belt structure. The hooks result in a seam in the belt that can cause a mark on the surface of the corrugated paperboard because of the reduced tendency of the belt to deflect in the seam area as compared with the more resilient surrounding portions of the belt.
Other problems that result from the use of present corrugator belts include poor frictional characteristics that result in slippage of the belt relative to the facing of the sheet of corrugated board that is being formed, stretching of the belt and sometimes breakage because of age of the fabric, and necking of the fabric, which is manifested as contraction widthwise of the belt if left stationary in contact with the heater plate of a corrugating machine. Further, conventional corrugator belts also sometimes run wet because of the absorption thereby of moisture, which leads to poor sheet drying, and possible sheet warping or curl, and they are also readily contaminated by glue or other materials and consequently require periodical removal for cleaning.
It is an object of the present invention to provide a corrugator belt structure that overcomes the deficiencies noted hereinabove with respect to the presently used corrugator belt structures.